When one or both of your legs shake, it is typically referred to as a tremor. This is an involuntary muscle contraction, meaning you are not in control of the leg movement.

Leg tremors may happen for many reasons and are not always a cause for concern. However, there are some conditions that cause leg shaking and may warrant a visit with your healthcare provider. Read on to learn more about what may be causing your legs to shake.  

What’s a Tremor?

Tremors are an involuntary movement that occur in predictable patterns. If you have a leg tremor, you will notice pulses or spasms in the muscle that typically last only a few minutes. In some cases, the tremors become chronic, which can indicate an underlying health issue.

Types

There are over 20 different types of tremors, but the most common types are:

  • Essential: Essential tremors are the most common. Medical researchers are not sure what causes essential tremors, but it is thought that a genetic component is involved. Essential tremors occur on both sides of the body and are typically mild, but they increase in severity as a person ages.
  • Dystonic: Dystonic tremors develop when a person has a type of movement disorder known as dystonia. Dystonia causes the signals from the brain to the muscles to go into overdrive, which essentially sends the wrong messages to the muscles and causes them to move involuntarily.
  • Cerebellar: Cerebellar tremors are visible to the naked eye and happen slowly following movement. They develop when the cerebellum, which controls our body’s movements, becomes damaged.
  • Psychogenic: Also referred to as a functional tremor, psychogenic tremors are associated with underlying psychiatric disorders. They can present as any form of tremor.
  • Physiologic: Physiologic tremors are normal human movements that happen to healthy individuals. The movements are so small, they can barely be seen and typically present in the hands or fingers as a mild shake.

Causes

Tremors and leg shaking can have various causes, including:

Enhanced Physiologic Tremors

Enhanced physiologic tremors are like physiologic tremors, however, they are more severe and visible to the eye. They are typically reversible because they are caused by things such as medication use, alcohol withdrawal, or certain non-life-threatening health conditions. 

Anxiety

Anxiety drives the body into a near-constant state of fight or flight. The fight-or-flight response is a reaction in the body that is designed to alert you to a threat and prepare you to survive. In people with anxiety, things that are not actually threats to one’s survival can set off that stress response in the body.

During that time, the hormone adrenaline is released and affects the muscles by pumping more blood into them. This response can also cause the legs to shake, and it can generate tremors in other areas of the body.

Primary Orthostatic Tremor

Primary orthostatic tremors are exclusive to the legs and cause quick muscle contractions when a person is standing up. A person with primary orthostatic tremors may also:

Anxiety and Tremors

Anxiety tremors fall under the category of psychogenic tremors. When a person has anxiety, they can experience several tremor-like sensations, such as muscle twitching, shaking, or trembling.

  • Feel unsteady or off-balanceFeel an urgent need to either sit down or walk

The tremor itself is so quick that it’s not easily seen, but when you place a hand on the area you can feel it.

Alcohol Withdrawal

Alcohol withdrawal can cause tremors that fall under the category of enhanced physiologic tremors. These shaking movements can develop because the use of alcohol can change how the nervous system functions.

Stimulants

Stimulants are medications designed to increase nervous system activity. They can be both prescription and recreational.

Alcohol Withdrawal and Leg Shaking

The body tremors that develop during alcohol withdrawal are typically called “the shakes,” and begin within five to 10 hours following a person’s last alcoholic beverage. The shakes can last for up to two days. 

These drugs can cause tremors to develop in all areas of the body, including the legs. While prescription stimulants can lead to tremors that go away after a person stops using the drug, recreational stimulants such as cocaine and ecstasy may cause a person to develop tremors that do not go away.

Parkinson’s Disease

Parkinson’s disease is a condition that affects the nervous system. People who develop Parkinson’s disease experience uncontrollable movements that progressively worsen over time. Tremors are typically the first warning sign that a person has the disease. Other symptoms of Parkinson’s include:

  • Muscle stiffness or rigidity in the arms and legsSlow movementsThe loss of reflexes and balance

Multiple Sclerosis

Multiple sclerosis is an autoimmune disease, which means that the immune system mistakenly attacks healthy cells.

The myelin sheath, the protective coating of nerve cells, becomes damaged by immune system cells because of MS. When that happens, the communication pathway between the brain and the body doesn’t function as it should leading to symptoms.

If a person with MS experiences nerve damage in cells that are in control of their muscle movements, they can develop tremors and leg shaking.

Dementia

Dementia is often associated with its worst symptom—memory loss—however, the condition does present with other symptoms as well.

MS and Tremors

While not everyone with MS will experience leg shaking or tremors, studies show that roughly 25%–58% of people with MS will have that symptom.

One such symptom is leg shaking or tremors. Because the disease is progressive and causes brain damage, it can affect movement in the body over time.

Other Causes of Leg Shaking

There are a few other reasons your legs may shake. These involuntary leg movements will typically not be rhythmic, though, and, therefore, are not a tremor.

Restless Legs Syndrome (RLS)

RLS looks the same as a tremor, however, it is different since it is a voluntary movement of the legs.

People with RLS have an uncontrollable urge to move their legs because of uncomfortable feelings such as tingling, burning, or pain. Itching and crawling sensations in the legs can also be present in people with RLS. These symptoms improve with movement and are typically worse at night.

RLS is commonly seen in people who are pregnant, have diabetes, or are deficient in certain nutrients. That being said, anyone can develop the syndrome.

Tourette’s Syndrome

Tourette’s syndrome is a type of neurological disorder that causes involuntary muscle spasms, or tics. Vocal outbursts are also a common symptom of Tourette’s. Typically, the syndrome develops slowly with tics occurring in the head or neck, although it can progress to the torso as well as the legs and arms.

ADHD

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder that typically begins in childhood. Neurodevelopmental disorders are considered disabilities and affect how the brain and neurological system functions. The symptoms associated with ADHD include:

  • Issues with paying attentionDifficulties practicing impulse controlBecoming overly active and having a hard time sitting still

Tardive Dyskinesia

In some cases, a person can develop shaking legs simply because of the medication they are taking. When that happens, it is referred to as Tardive dyskinesia, which is categorized as an involuntary movement disorder.

Leg Shaking and ADHD

Leg shaking may be a symptom of ADHD because people with the disorder often fidget or squirm because of hyperactivity.

The movements or shaking can occur throughout the entire body. Medications that can cause Tardive dyskinesia include:

  • Antipsychotics used to treat mental disorders such as schizophrenia
  • Anticholinergic agents used to treat chronic obstructive pulmonary disease (COPD), which is a group of lung disorders, and Parkinson’s disease
  • Antidepressants used to treat mental health disorders such as anxiety, depression, and ADHD
  • Antiemetics used to treat severe nausea and acid reflux (stomach acid or bile goes back up the food pipe)
  • Anticonvulsants used to treat seizures
  • Antihistamines used to treat allergy symptoms
  • Decongestants used to treat the symptoms of colds and flu
  • Antimalarials which are used to prevent and treat malaria (a serious disease caused by a parasite)
  • Medications used to treat Parkinson’s disease
  • Anxiolytics used to treat anxiety
  • Mood stabilizers used to treat bipolar disorder and other mental health disorders

Treatment

Treatment options vary widely for tremors because of the varied causes. In some cases, leg shaking doesn’t require treatment at all because it is simply temporary and will go away on its own.

If a person has developed leg shaking because of a specific health condition, that underlying disease will be treated, and the shaking will likely improve because of it. Other options for treatment that may be suggested along with disease-specific remedies include:

  • Stress management and relaxation techniques such as yoga or massage can be used to help leg shaking that is caused by anxiety or Parkinson’s disease.
  • Avoiding certain triggers such as stimulants, alcohol use, or other drugs that cause leg shaking.
  • Surgery such as deep brain stimulation if no other treatments are working and the leg shaking is significantly interfering with your life.

Prevention

In many cases, especially if leg shaking is caused by an underlying health condition, you cannot prevent the tremors from occurring. The best thing you can do to prevent tremors is to pay attention to other symptoms that occur alongside them, take care of your health as best as possible, and seek out medical advice if the tremor has become bothersome or doesn’t go away.

When to See Your Healthcare Provider

Leg shaking may be worrisome, although it is not always indicative of a serious disease. If you are experiencing other symptoms, including difficulty with walking or standing, controlling your bladder or bowels, cognitive changes, or vision loss, visit a healthcare professional. You may have an underlying health condition that requires treatment.

A Word From Verywell

Uncontrolled movements like leg shaking and tremors can seem troublesome at first, but in many cases, they are harmless and will go away on their own.

If you are worried about your leg shaking or if it interferes with your daily life, contact your healthcare provider. They will be able to administer the proper tests to diagnose a possible cause, and offer tips on how to cope with leg shaking and potentially prevent it, if possible.

Frequently Asked Questions

  • Can medications cause tremors?
  • Certain types of medications have been known to cause tremors. When medications do cause a movement disorder, it is typically referred to as Tardive dyskinesia. In many cases, the tremor will resolve once you stop taking the medication.
  • What causes tremors when sleeping?
  • Many things can cause tremors to develop during sleep. When they do, it is referred to as sleep myoclonus. Sleep myoclonus is not a disease in itself but a symptom of an underlying health condition.

Certain types of medications have been known to cause tremors. When medications do cause a movement disorder, it is typically referred to as Tardive dyskinesia. In many cases, the tremor will resolve once you stop taking the medication.

Many things can cause tremors to develop during sleep. When they do, it is referred to as sleep myoclonus. Sleep myoclonus is not a disease in itself but a symptom of an underlying health condition.